JcloudsLocationCustomizer: methods take JcloudsLocation

- pass JcloudsLocation as first arg to each method of customiser
- BasicJcloudsLocationCustomizer has deprecated old-style methods
  that are delegated to, for backwards compatibility
Adds JcloudsLocatin.JCLOUDS_LOCATION_CUSTOMIZER_TYPE

- For reflectively instantiating a customiser instance for a given type,
  based on config values.
Merge pull request #934 from aledsage/fix/JcloudsLocationCustomizer-pass-JcloudsLocation-arg

JcloudsLocationCustomizer: methods take JcloudsLocation